When a shadowrunning team tries to break into a facility protected by magic, it seems to me as a GM like the team's biggest liability is getting past magical security. If a mundane B&E character tries to use Infiltration to get up close to the facility, a watcher spirit, bound spirit, or astrally projecting security mage can spot them, because they're lit up like a torch in the astral plane.

This gives rise to closely-related questions:

As a GM, how should I handle stealth vs. a spirit or astral projection? Should I make the astral being roll Perception (or Assensing?) against the stealthy character's Infiltration? Is it possible for the character to be stealthy without a spirit providing the Concealment power?

If the observing entity is a spirit, is there a way for the intruding team's mage to misdirect the spirit so that the intrusion goes unnoticed?

How can a mage on the intruding team go unnoticed when astrally projecting to scope out the site?

2 Answers
2

So, as you said there are several cases. Lets go through them in turn:

As a GM, how should I handle stealth vs. a spirit or astral
projection?

There is some information on this on the Shadowrun FAQ (Under the Astral subheading), although it speaks only of dual-natured or projecting characters. For dual-natured characters, it is an opposed Infiltration vs. Assensing test using the modifiers from pg. 114 of Street Magic (Basically a penalty if you're sneaking by all alone, or a bonus if there is a lot of stuff and people in the area). While the rules don't explicitly allow it, I'd use the rules outlined for dual-natured characters for standard characters as well- possibly with an extra penalty.

If the observing entity is a spirit, is there a way for the intruding
team's mage to misdirect the spirit so that the intrusion goes
unnoticed?

Absolutely, and really there are as many ways as you might misdirect a real guard. Create a disturbance, use an illusion, be found and then lead the spirit away. There are a lot of great options for the PC.

How can a mage on the intruding team go unnoticed when astrally
projecting to scope out the site?

Stealth is applicable if there are plenty of astrally-interesting objects around. For example, if there are lots of plants, other people, etc., then an opposed test is reasonable (or if the spirit has a very large area to cover). Otherwise, no, if you're lit up like a torch, you can't really be "stealthy".

Most things that a mage can do to a spirit (like attempt to take control of it from its summoner) will tend to alert the summoner. However, spirits can be distracted. I'd allow that a reasonable chance of success (at least enough to enable the infiltration opposed test above) if the players come up with something sensible. Combat is probably not a good idea, but perhaps the mage could summon a spirit that would tease the sentinel spirit about being forced to do such a boring job, while it is free to run around.

The best hope for an astrally projecting mage on the intruding team is to get in so fast that no-one notices--or at least it used to be in SR3. I'm not sure if you can still launch yourself into an area at fast astral speeds (if the GM will let you), and then figure out where exactly you are when you slow down.